(1) Field of the Invention
The present invention relates to a recording medium, such as a DVD, a recording apparatus, a reading apparatus, and a program. More particularly, the present invention relates to an improvement on personal use of copy righted digital contents on a home network.
(2) Description of the Related Art
In research and development on recording mediums and recording apparatuses, one important issue is how to provide home network adaptability to recording mediums and recording apparatuses. A home network is a type of local area network constructed with appliances each having a digital interface that are interconnected to one another via a digital cable such as IEEE1394. With a home network incorporating an STB (Set Top Box), a digital TV, a personal computer, and a recording apparatus, a user can receive digital data with the personal computer or the STB, and transmit the digital data over the home network to the digital TV, which may be located in a separate room within a same household, to play back the digital data. Further, the user can record the digital data on a DVD using the recording apparatus, which may be located in another separate room within the same household. In short, a home network makes it possible to share digital data among networked appliances, which significantly improves the convenience of users.
However, free distribution of digital data over a home network gives a rise to a problem on copyright protection of copyrighted video data and audio data. As long as it is on a home network and for personal use, copying or playback of a copyrighted digital content will not violate the distribution right, the reproduction right, and the communication right. Such use of digital contents on a home network is only for personal use and thus is not subjected to copyright protection. Techniques for recording digital video data onto a DVD for making a personal copy are disclosed, for example, in U.S. Pat. No. 6,272,286 and Japanese Patent No. 3162044.
Problems associated with personal copying include what copyright protection is to be applied to video data recorded on a recording medium, and whether to permit copying of such video data. It is undesirable to apply no copyright protection to personal copying of digital data on a home network. This leads to undesirable possibility that unauthorized copies of the video data made on a home network are uploaded to sites on the Internet and distributed to public without the consent of the copyright holders. However, it is not desirable either to impose limitation on personal copying of video data by imposing copy control information, as disclosed in the above stated patents, such as “Only One Copy” where copying of the video data is permitted only once, and “No More Copy” where no copying of the digital data is permitted. This leads to that users cannot fully enjoy their rights to copy any digital data for personal use, which tends to invite resistance from the users.
Above problems are more notable in connection with TV programs since the right to make a personal copy of a TV program has long been taken for granted. Distribution of digital data that is obtained by encoding a TV program infringes the copyright holder's right. With pirate versions being widely distributed, the TV program put into the market as an authorized software package would not sell well. On the other hand, however, it is unacceptable for users to be prohibited from making a personal copy of the digital data despite that it technically possible to make such a copy in good quality. Conventionally, there is no copy control technique that protects the rights of both copyright holders and users in good balance. With this being the situation, manufacturers of home appliances are pushed into a difficult position.